This study examines the psychological and biological effects of sexual abuse on female children and adolescents. Subjects are 90 sexually abused females (6 to 15 years of age) and their mothers (or other non-abusing caretaker) and 90 demographically similar non-abused girls and their mothers. A cross-sequential design is employed and both cross-sectional and longitudinal data are collected at three yearly intervals. A multi-method approach to data collection includes Tanner staging of pubertal stage; assaying of blood hormonal levels; standardized tests and interviews of child and parent; observation of parent-child interaction; and records from schools, teachers and other agencies. The main hypotheses being tested are that (1) sexually abused girls will have a more difficult transition through puberty; (2) sexual abuse alters hormonal levels and affects the timing of puberty; and (3) that sexually abused girls will maintain higher levels of dissociation into adolescence.